Basement Venting Question
Just wondering if I can I put in a 2" common vent upstream from shower draining into a 3" line with a toilet downstream from the shower? If not, what are my options in this simple fixture layout? The total length of the 3" run is no more than from main and the length of each fixture drain is no more than 2.5 feet.
I do appreciate your consideration and enjoy reading your plumbing advice on askmehelpdesk.com. If you would like me to post the question, I'm happy to do so. (I just did Gary!)
Gary.
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Attachment : basement.TIF (0.02 MB)
Attached is the simple layout of the basement bathroom I would like to install with a toilet downstream from a shower both drained into a 3" branch t'd off the 4" main.
Can I use circuit venting by putting in a 3x3x2 T off the 3" branch between the toilet and shower with the takeoff from the T running vertically? Alternatively, could I extend the 3" branch and put in a circuit vent upstream from the shower and add a cleanout for convenience? Wet venting won't work since Minnesota building code restricts went venting to 4 f.u. and the toilet alone is 6.
Thanks again for being so helpful. This venting question has been very vexing.
Gary.
Hi Gary,
Let's get a few terms atraight. What you are suggesting isn't a Circuit or Loop Vent which is a battery of vents for up to 8 fixtures connected by a Loop leading to a Common Vent out the roof. You're suggesting a Individual or Common Vent that ties 2 fixtures that drain on the same level.
You may vent from the 3" branch with a upright combo or drainage tee. You may also wye off the shower drain and add a clean out providing that your distance between shower trap and vent doesn't exceed 5' for a 2" vent or 6' for a 3" vent. Unless your local codes dictate that each fixture be individually vented Section 1413.1 under Chapter 14 ,Vents and Venting of The Standard Plumbing Code allows a Common Vent for a entite bathroom group providing they enter the stack at the same level so that would provide venting for your toilet also. I hope this answers your questions. Good luck. Tom
One last detail - horizontal venting
Just one last detail that might change your answer: All the drains, branch and main in the diagram are horizontal - since it's all going in the basement. All references to Common Vent in the local code pertained to vertical stack. My layout is close to where the main line exits the house.
Again, thanks for your help.
